Apparatus and method of flash butt welding of railway lines

Abstract

This invention relates to a flash butt welding process for joining sections of a railway line using vibration apparatus, the process including configuring and attaching a vibration apparatus on the railway line such that a vibration means is attachable to the railway line, and controlled vibration of the railway line at a suitable low frequency of vibration and amplitude of vibration, and then welding sections of railway line together using a flash butt welding means, and applying vibration to the sections of railway line until the flash butt weld is complete, and applying a controlled vibration to the welded sections of railway line for a period of time sufficient to allow for heat to dissipate from the weld area, and to allow for the weld area to be stress relieved for an improved weld joint.

The invention claimed is: 
     
       1. A flash butt welding process for joining axially aligned sections of railway line, the ends of the aligned sections of railway line forming a weld area, the process including the step of:
 a. aligning the sections of railway line axially using alignment clamping means, and attaching a vibration apparatus on the railway line, the vibration apparatus including a vibration control means and a vibration means, the vibration control means being configured and arranged to control a frequency of vibration and amplitude of vibration being applied by the vibration means to the sections of railway line, the vibration control means receiving signals from a frequency of vibration measurement means, an amplitude of vibration measurement means, and a temperature measurement means, and vibrating the sections of railway line at a low frequency of vibration and amplitude of vibration, the frequency of vibration and amplitude of vibration being preset, and being adjustable during the process by the vibration control means; 
 b. welding the ends of the aligned sections of railway line together using a flash butt welding means and by applying electrical current to the sections of railway line and raising the temperature of the line to an operating temperature, and longitudinally separating and then flashing and forging by pressing together the ends of the aligned sections of railway line with force, and applying vibration to the sections of railway line until the flash butt weld is complete; and after releasing the clamping-means, 
 c. applying vibration to the welded sections of railway line for a period of at least 5 minutes after welding is completed to allow heat to dissipate from the weld area, and to allow for the weld area to be stress relieved. 
 
     
     
       2. A flash butt welding process according to  claim 1  wherein the vibration apparatus applies a controlled vibration about the weld area for a period of between 5 to 25 minutes after welding is completed. 
     
     
       3. A flash butt welding process according to  claim 1  wherein the vibration apparatus applies a controlled vibration to the weld area for a period of between 5 to 25 minutes after a pause for 5 minutes upon release of the alignment clamping means about the weld area. 
     
     
       4. A flash butt welding process according to  claim 1  wherein the vibration means is a motor provided with eccentric weights applied to the shaft of the motor, and wherein the motor is clampable to a said section of railway line adjacent the weld area. 
     
     
       5. A flash butt welding process according to  claim 1  wherein the frequency of vibration measurement means is a tachometer means being releasably attachable to the railway line, and the amplitude of vibration measurement means is a velocity meter or an accelerometer means being releasably attachable to the railway line, the tachometer means and the velocity meter or the accelerometer means being adapted to provide feedback signals to the vibration control means. 
     
     
       6. A flash butt welding process according to  claim 1  wherein the frequency of vibration applied by the vibration apparatus is between about 50 Hertz and 800 Hertz. 
     
     
       7. A flash butt welding process according to  claim 1  wherein the frequency of vibration is between about 85 to 90 Hertz, and the amplitude of vibration is between about 0.5 millimeters to about 2 millimeter per second. 
     
     
       8. A flash butt welding process according to  claim 1  wherein the amplitude of vibration applied is about 0.5 millimeters per second. 
     
     
       9. A flash butt welding vibration apparatus for carrying out a flash butt welding process for joining axially aligned sections of railway line, wherein aligned ends of the sections of railway line will for a weld area, the vibration apparatus being configured and arranged in association with a flash butt welding apparatus, the vibration apparatus including a vibration control means and a vibration means, the vibration control means being configured and arranged to control a frequency of vibration and amplitude of vibration being applied by the vibration means to the railway line, the vibration control means receiving signals from a frequency of vibration measurement means, an amplitude of vibration measurement means, and a temperature measurement means, and to apply a constant vibration to the welded sections of railway line for a period of at least 5 minutes after welding is completed to allow heat to dissipate from the weld area, and to allow for the weld area to be stress relieved.